cfi_flash: precision and underflow problem in tout calculation

With old configuration it could happen tout=0 if CONFIG_SYS_HZ<1000. Signed-off-by: Renato Andreola <renato.andreola@imagos.it> Signed-off-by: Alessandro Rubini <rubini@gnudd.com> Signed-off-by: Thomas Chou <thomas@wytron.com.tw> Signed-off-by: Stefan Roese <sr@denx.de>

cfi_flash: precision and underflow problem in tout calculation
With old configuration it could happen tout=0 if CONFIG_SYS_HZ<1000. Signed-off-by: Renato Andreola <renato.andreola@imagos.it> Signed-off-by: Alessandro Rubini <rubini@gnudd.com> Signed-off-by: Thomas Chou <thomas@wytron.com.tw> Signed-off-by: Stefan Roese <sr@denx.de>
Renato Andreola · Stefan Roese
1 parent 7027d5622d
Showing 1 changed file with 4 additions and 1 deletions Side-by-side Diff
drivers/mtd/cfi_flash.c
@@ -537,7 +537,10 @@
 	ulong start;
  
 #if CONFIG_SYS_HZ != 1000
-	tout *= CONFIG_SYS_HZ/1000;
+	if ((ulong)CONFIG_SYS_HZ > 100000)
+		tout *= (ulong)CONFIG_SYS_HZ / 1000;  /* for a big HZ, avoid overflow */
+	else
+		tout = DIV_ROUND_UP(tout * (ulong)CONFIG_SYS_HZ, 1000);
 #endif
  
 	/* Wait for command completion */
...	...	@@ -537,7 +537,10 @@
537	537	ulong start;
538	538
539	539	#if CONFIG_SYS_HZ != 1000
540		- tout *= CONFIG_SYS_HZ/1000;
	540	+ if ((ulong)CONFIG_SYS_HZ > 100000)
	541	+ tout = (ulong)CONFIG_SYS_HZ / 1000; / for a big HZ, avoid overflow */
	542	+ else
	543	+ tout = DIV_ROUND_UP(tout * (ulong)CONFIG_SYS_HZ, 1000);
541	544	#endif
542	545
543	546	/* Wait for command completion */